FFT implementation cache changes

src/Basic.cpp

@@ -68,7 +68,7 @@ void Basic::analyseGrain(const float *data, std::ptrdiff_t stride)
 
 		auto log2TransformLength = input.applyAnalysisWindow(ref);
 
-		Fourier::transforms.forward(log2TransformLength, input.windowedInput, grain.transformed);
+		Fourier::transforms->forward(log2TransformLength, input.windowedInput, grain.transformed);
 
 		const auto n = Fourier::binCount(grain.log2TransformLength) - 1;
 		grain.validBinCount = std::min<int>(std::ceil(n / grain.resampleOperations.output.ratio), n) + 1;
@@ -112,7 +112,7 @@ void Basic::synthesiseGrain(OutputChunk &outputChunk)
 		else
 			grain.transformed.topRows(grain.validBinCount).colwise() *= t;
 
-		Fourier::transforms.inverse(grain.log2TransformLength, output.inverseTransformed, grain.transformed);
+		Fourier::transforms->inverse(grain.log2TransformLength, output.inverseTransformed, grain.transformed);
 	}
 
 	output.applySynthesisWindow(log2SynthesisHop, grains, output.synthesisWindow);

src/Basic.h

@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include "Fourier.h"
 #include "Grains.h"
 #include "Input.h"
 #include "Output.h"
@@ -11,6 +12,7 @@
 namespace Bungee {
 
 struct Basic :
+	Fourier::Bootstrap,
 	Timing
 {
 	Input input;

src/Fourier.cpp

@@ -57,7 +57,13 @@ void Kiss::Kernel<isInverse>::inverse(int, float *t, std::complex<float> *f) con
 	kiss_fftri((kiss_fftr_cfg)implementation, (kiss_fft_cpx *)f, t);
 }
 
-static Fourier::Cache<Kiss, 16> cache;
-Transforms &transforms = cache;
+Transforms *transforms{};
+
+Bootstrap::Bootstrap()
+{
+	BUNGEE_ASSERT1(!transforms);
+	static Fourier::Cache<Kiss, 16> cache;
+	BUNGEE_ASSERT1(transforms == &cache);
+}
 
 } // namespace Bungee::Fourier

src/Fourier.h

@@ -74,7 +74,7 @@ struct Transforms
 	virtual void inverse(int log2TransformLength, Eigen::Ref<Eigen::ArrayXXf> t, const Eigen::Ref<const Eigen::ArrayXXcf> &f) const = 0;
 };
 
-extern Transforms &transforms;
+extern Transforms *transforms;
 
 // General case when an FFT implementation has different states for forward and reverse transforms of same size.
 template <class F, class I>
@@ -133,6 +133,11 @@ struct Cache :
 
 	Table table;
 
+	Cache()
+	{
+		transforms = this;
+	}
+
 	void prepareForward(int log2Length) override
 	{
 		std::scoped_lock lock(preparationMutex);
@@ -172,4 +177,9 @@ struct Cache :
 	}
 };
 
+struct Bootstrap
+{
+	Bootstrap();
+};
+
 } // namespace Bungee::Fourier

src/Input.cpp

@@ -19,7 +19,7 @@ Input::Input(int log2SynthesisHop, int channelCount) :
 	windowedInput{(8 << log2SynthesisHop), channelCount}
 {
 	windowedInput.setZero();
-	Fourier::transforms.prepareForward(log2SynthesisHop + 3);
+	Fourier::transforms->prepareForward(log2SynthesisHop + 3);
 }
 
 int Input::applyAnalysisWindow(const Eigen::Ref<const Eigen::ArrayXXf> &input)

src/Output.cpp

@@ -12,7 +12,7 @@ Output::Output(int log2SynthesisHop, int channelCount, int maxOutputChunkSize, f
 	inverseTransformed(8 << log2SynthesisHop, channelCount),
 	bufferResampled(maxOutputChunkSize, channelCount)
 {
-	Fourier::transforms.prepareInverse(log2SynthesisHop + 3);
+	Fourier::transforms->prepareInverse(log2SynthesisHop + 3);
 }
 
 void Output::applySynthesisWindow(int log2SynthesisHop, Grains &grains, const Eigen::Ref<const Eigen::ArrayXf> &window)

src/Window.cpp

@@ -22,8 +22,8 @@ Eigen::ArrayXf fromFrequencyDomainCoefficients(int log2Size, float gain, std::in
 	frequencyDomain.bottomRows(frequencyDomain.rows() - i).setZero();
 
 	Eigen::ArrayXf window(1 << log2Size);
-	Fourier::transforms.prepareInverse(log2Size);
-	Fourier::transforms.inverse(log2Size, window, frequencyDomain);
+	Fourier::transforms->prepareInverse(log2Size);
+	Fourier::transforms->inverse(log2Size, window, frequencyDomain);
 	return window;
 }